Figure 3. RIXS spectra of Na₃Ir₃O₈ single crystal and polycrystalline Na₄Ir₃O₈ at Ir L₃-edge.

The two spectra were normalized by the intensity of the high energy tail above 6 eV. The blue and pink solid lines around zero energy show the normalized elastic signals independently measured with σ-polarized incident X-ray.